This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In digital media systems it is sometimes useful to be able to distinguish between live content and recorded content. An exemplary reason for this is that, for example in the requirements defined by the Digital Video Broadcast Copy Protection (DVB) Group, proximity control does not apply to a content forever but will be relaxed when a certain predetermined condition is met. A first possible condition is that proximity control is relaxed as soon as the content is no more live. A second possible condition is that it is relaxed after a fixed amount of time following the live broadcast. A third possible condition is that it is relaxed at a fixed date. It can be seen, however, that the first and the third conditions may be seen as variations on the theme of the second condition: the fixed amount of time is zero for the first condition, and to whatever time it needs to arrive at the date for the third condition. Other exemplary conditions are conditional; proximity control may for example be relaxed if a user has paid extra to access the content, if the user has a certain user profile, or as soon as a certain content is broadcast.
Another example is the limitation of the number of concurrent consumptions of a content. In the DVB group, this limitation is only required for live content and can be relaxed once the content is no longer live.
One method of distinguishing between live and recorded content within a home network is to have the rendering device determine whether the content it is receiving comes from a storage device—recorded content—or from an Acquisition Point, which is the device through which the content enters the home network—live content.
However, a problem may occur when the storage device is capable of so-called trick modes, e.g. replaying live content after a short delay. In this case, the rendering device is led to believe that the content is recorded, while it in fact should be regarded as live content at least for as long as the Acquisition Point is diffusing the content. In this case, trick modes are easy circumvention tools for the proximity control; a user would just have to watch the content with a delay of, say, five seconds to bypass the control.
WO 2006/082130 discloses a solution to the “trick-mode” problem, in which the consumption device broadcasts a message to check whether the content is live or not. If the Acquisition Point answers, content will be considered live, else it will be considered as recorded. A possible circumvention to that solution would be to first record part of the content (e.g. 30 minutes) and then start recording on a second recording device, disconnect the first recording device and the consuming device from the network and play the first part of the content. After 30 minutes, one could disconnect the second recording device and reconnect the first recording device and continue the recording on it. The second recording device would then be used to display the content recorded thereon. As the consuming device is never connected to the Acquisition Point, even using the solution of WO 2006/082130, content would be no more considered as live while a recording device is still recording it.
It can therefore be appreciated that there is a need for a solution that allows a rendering device to distinguish between live content and recorded content, including when trick mode is used or when content is recorded using multiple recording devices. This invention provides such a solution.